The invention of this application relates to power lawn implements and more specifically to a device for reducing, i.e. pulverizing and comminuting, debris such as leaves and cut grass, commonly found on lawns, to reduce the size of such debris so that it may be redeposited on the lawn surface between, rather than atop, the growing grass filaments. It also relates to a device for raking lawns to lift and separate material commonly called "thatch," i.e. matted dead grass and debris which collect on a lawn surface at the ground level, from growing grass filaments. Debris reducing implements improve the appearance of lawns by particlizing large pieces of debris lying atop the grass filaments and redepositing the particlized matter back into the lawn at the ground level where the matter may decay and provide fertilization of the lawn. Power-raking implements promote healthful growth of the lawn by removing the thatch. If thatch is not periodically removed, it may create a barrier through which air and water may not easily penetrate to the soil and also may provide an environment which encourages harmful fungus growth.
The most common type of lawn debris reducing implement in use today for residential lawn application is of the walk-behind rotary type. Typically, these walk-behind rotary implements have one or more blades configured to accomplish the pulverizing and comminuting function. The blade or blades are commonly mounted on a shaft attached to the implement proper, the shaft oriented generally perpendicular to the plane of the ground.
Such implements are not typically suited to provide the dual function of removing thatch and reducing debris, and will often only marginally perform the debris reducing task. Lawn debris reducing blade numbers and arrangements are frequently inadequate to accomplish the desired particlization of the debris. A horizontal orientation of the blade may also decrease the amount of time during which debris is exposed to the reducing process and allow debris movement in the direction of the blade so that only a small velocity differential exists between the blade and debris. Minimizing the velocity differential precludes efficient particlizing. Furthermore, rather than directing the particlized debris back toward the lawn and forcing it down into the grass growing thereon, the debris is, rather, allowed to merely settle in the upper extremities of the grass. Only minimal protection and fertilization is thus realized.
The invention of the present application may, in certain embodiments, function both as a debris reducing implement and a power rake for removing thatch. Because of its debris processing element structure and orientation, it is capable of converting debris to a very fine particulate size and redepositing the reduced debris well beneath the upper extremities of the grass.